This invention relates to a waterproof testing apparatus for a grommet.
FIG. 7 is a plan view of a known grommet of which a waterproof state is tested with use of an apparatus according to this invention.
The grommet 1 shown in FIG. 7 is arranged at a certain position on a tube 2 for inserting a wire harness. The grommet 1 has a flange portion 3 fittingly mounted in an insertion hole of a partition wall of a vehicle body. The flange portion 3 has a main insertion portion 3a at a generally middle part thereof for passing a primary trunk part of the wire harness, and a small-diametrical sub insertion portion 4 at a position radially away from the main insertion portion 3a in eccentric therewith. The sub insertion portion 4 includes a boss portion 5 for passing a relatively small number of wirings W in a bundle.
FIG. 8 is a cross sectional view showing a state that the sub insertion portion 4 of the grommet shown in FIG. 7 is being fastened.
As shown in FIG. 8, a polyurethane sheet 6 is wound around the outer circumferential surface of the wiring bundle W with an end portion thereof accommodated in a space between the wirings in order to secure sealability between the inner peripheral surface of the sub insertion portion 4 and the wiring bundle W. A clamp belt 7 wound around the outer peripheral surface of the boss portion 5 is pulled in the direction of arrow A in FIG. 8 to fasten the boss portion 5. Thus, a waterproof state of the grommet is secured.
Heretofore, there has been proposed an apparatus for testing a waterproof state of the main insertion portion of the grommet 1. However, an apparatus for checking whether the sub insertion portion 4 has a waterproof structure has not been put into practice so far.
In view of the above, it is an object of this invention to provide a waterproof testing apparatus for a grommet capable of easily and accurately testing whether a sub insertion portion provided in eccentric with a main insertion portion of the grommet has a waterproof structure.
To accomplish the above object, this invention is directed to an apparatus capable of easily and accurately testing whether a sub insertion portion of a grommet is in a good waterproof state, in which the grommet is provided with a flange portion mountable on a vehicle body, a main insertion portion formed on the flange portion for inserting a bundle of wirings, and the sub insertion portion provided in eccentric with the main insertion portion.
The testing apparatus according to an aspect of this invention comprises enclosing means which sealably encloses an end portion of the sub insertion portion, air feeding means which feeds air for testing to a space of the enclosing means in which the sub insertion portion is sealably accommodated, and judging means which judges a waterproof state of the sub insertion portion based on a status of the air fed by the air feeding means.